2.92, Simple Boolean, Won't Work... Why?
1.) select channel

2.) Tab -&gt; change to edit mode
3.) A -&gt; select all
4.) mesh -&gt; normals -&gt; recalculate outside

5.) select all vertices at the end of your channel and press 'f' to create a closing face (make sure you are in &quot;vertex select&quot; mode


6.) tab -&gt; object mode
7.) change to &quot;display as&quot; -&gt; bounds
8.) result